Grafana Labs employee here. We've been using jsonnet-bundler as a package manager on top of our Tanka configs. As for some common packages, we open source most of ours[1]. We also provide Tanka-compatible configs for Loki[2].

[1]: https://github.com/grafana/jsonnet-libs

[2]: https://github.com/grafana/loki/tree/master/production/ksonn...